For the production of a textile cross-wound bobbin it is well known on the one hand that is necessary for the relevant textile bobbin to be set into rotation and on the other hand that the yarn running onto the bobbin needs to be traversed during the winding process relatively rapidly along the bobbin axis. The textile bobbins formed in this way then have a so-called cross winding and are characterized not only by having a relatively stable bobbin body but also by exhibiting good reeling behaviour.
In connection with the production of such cross-wound bobbins various different yarn traversing devices have been known for a long time, which are described in a relatively large amount of detail in numerous patent applications.
For example in cross-wound bobbin machines which operate at relatively high winding speeds, it is common to use so-called yarn guiding drums as yarn traversing devices at the workstations. Such yarn guiding drums each have an endless groove for traversing the on-running yarn and at the same time drive the textile bobbins in a frictional manner.
However, depending on the system these types of tried and tested yarn guiding drums only enable the production of cross-wound bobbins with a “wild” type of winding. Furthermore, such yarn guiding drums are relatively complicated to produce and are therefore expensive.
However, in the textile industry textile machines producing cross-wound bobbins with spooling devices have also been known for a long time which if necessary also enable the production of cross-wound bobbins which are wound with a “precision” type of winding.
Such textile machines each have in the region of their workstations a device for rotating a textile bobbin and a separate device for traversing an on-running yarn. For example, a drivable bobbin drive drum is used as the rotation device, whilst a mechanism is often used as a yarn traversing device which is equipped with a so-called inverse yarn guide.
In German Patent Publication DE 38 01 980 C2 for example a textile machine producing cross-wound bobbins is described, in which the workstations are each equipped with a yarn traversing device which has an inverse yarn drum, to which the yarn guide of the workstation is connected.
As such inverse yarn drums are mostly lubricated with oil or grease, the inverse yarn drum is surrounded respectively by an inverse yarn housing, which has a slot through which a carrier or a shuttle of the yarn guide projects into the groove of the inverse yarn drum.
To prevent oil or grease escaping out of the yarn guide slot of the inverted yarn housing or prevent textile dust from entering through the slot into the inverted yarn housing, the slot of the inverted yarn housing is generally sealed by a cover connected to the yarn guide, which also denoted as a sealing lip.
A considerable disadvantage of such inverted yarn gears is however that inverted yarn drums are also relatively expensive to produce.
Therefore, in order to reduce the manufacturing costs of such textile machines producing cross-wound bobbins it has already been proposed to simultaneously drive the yarn guides of a plurality of workstations of such a textile machine arranged next to one another by means of a single inverse yarn drum.
In German Patent Publication DE 195 36 761 A1 for example a winding machine is described in which the yarn guide of the yarn traversing devices of a plurality of workstations are operated simultaneously in that a yarn guide driven by an inverted yarn drum is connected by a suitably long sealing lip to the yarn guides of adjacent workstations.
By means of such a construction the manufacturing costs of the yarn traversing devices could be reduced; however as with all inverted yarn gears the aforementioned embodiment has the disadvantage that such inverted yarn gears require a considerable amount of maintenance.
A further disadvantage of such yarn traversing devices with inverted yarn gears is that such inverted yarn gears are relatively loud during operation and that the traversing speeds achievable by means of such devices are relatively low.
Therefore in the past, to increase the traversing speed of textile machines producing cross-wound bobbins, it has already been proposed to connect the yarn guides of the workstations by an endless tensioning means to a reversible, electric motor single drive, which can be driven in a defined manner by an associated control device.
From German Patent Publication DE 37 34 478 A1 for example a yarn traversing device is known in which a yarn guide guided in the region of a workstation on a yarn guide rod is connected by an endless tensioning means to an electric motor single drive, which is designed as a microprocessor-controlled stepping motor.
In this known yarn traversing device both the yarn guide guided on a yarn guide rod and the endless tensioning means are completely free and are thus exposed without protection to the unavoidable textile dust or airborne fiber produced during the winding process.
Similar freely exposed yarn traversing devices with a yarn guide connected by an endless tensioning means to an electric motor single drive are also described in European Patent Publication EP 0 950 631 A1 and/or German Patent Publication DE 103 00 106 A1.
In said known yarn traversing devices the endless tensioning means designed as a drive band or drive belt is guided by a drive wheel connected to a single drive and two guide wheels arranged laterally relative to the traversing area of the workstation.
However, said extremely advantageous yarn traversing devices also have the disadvantage that they are very susceptible to textile dust or airborne fibers which are unavoidable particularly in spooling areas. This means that the aforementioned yarn traversing devices require a considerable amount of continuous cleaning in order to be operated correctly over a longer time period.
The yarn traversing device described in Swiss Patent Publication CH-PS 510 580 also requires such a large amount of cleaning.
In this yarn traversing device in the region of the workstations of a spooling machine two opposite running yarn guides are used. This means that the yarn guides are connected respectively to a drivable endless tensioning means in the form of a toothed belt, wherein one toothed belt rotates clockwise and the other toothed belt rotates anti-clockwise.
The two contrary rotating toothed belts are also each guided with their toothing over a plurality of guide wheels which are designed in the form of lock washers.
Furthermore, from German Patent Publication DE 10 2004 003 173 A1 a yarn traversing device is the prior art for a spooling device of a textile machine producing cross-wound bobbins, in which the endless tensioning means, to which the yarn guide is connected, rotates in a housing of the yarn traversing device which is closed as far as possible. The endless tensioning means designed as a toothed belt is connected to a single drive, that is the toothed belt runs over guide wheels arranged laterally next to the traversing area and over the drive gear of an electric motor single drive.
The yarn traversing device described in German Patent Publication DE 10 2004 003 173 A1 is a clear improvement over the previously known yarn traversing devices, in particular with regard to the cleaning required, however it has the disadvantage that some specific cleaning is necessary on a continual basis.
After a certain operating period of the yarn traversing device problems often occur, for example in the region of the endless tensioning means, particularly in the region of the guide wheels. This means in this known yarn traversing device that, despite the housing which is closed on all sides, fiber residue and dirt particles settle in the region of the toothing of the guide wheels which fiber residue and dirt particles are also additionally compressed by the toothing of the endless tensioning means.
The build-up of fiber residue and dirt particles means that over time the toothed belt is lifted slightly in the region of the guide wheels, which results in negative changes to the predefined traversing width to be covered by the yarn guide.